Artefacts with Eevee
It was a driver problem. The affected computer model is from the ASUS UX410 series. The Intel update refuses to install the new driver and refers to a customized driver from the manufacturer. However, the automatic update function of the manufacturer does not find the new Intel driver, but it is listed on the manufacturer's website. 

I installed the driver and the problem was fixed. There are no artifacts in the viewport now and the render is clean.